Answer: D) Covalent- network Explanation: Graphite is a covalent-network type of crystalline solid.   There are two main categories of solids. 1. Crystalline solids and 2. Amorphous solids. Crystalline solids are those in which the atoms, ions, or molecules that make up the solid exist in a regular, well-defined arrangement. There are four types of crystalline solids : Ionic solids :— Made up of positive and negative ions and held together by electrostatic attractions. They’re characterized by very high melting points and brittleness and are poor conductors in the solid state. An example of an ionic solid is table salt, NaCl. Molecular solids :— Made up of atoms or molecules held together by London dispersion forces, dipole-dipole forces, or hydrogen bonds. Characterized by low melting points and flexibility and are poor conductors. An example of a molecular solid is sucrose. Covalent-network (also called atomic) solids :— Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes. As you can see below, graphite has only 2-D hexagonal structure and therefore is not hard like diamond. The sheets of graphite are held together by only weak London forces! Metallic solids :— Made up of metal atoms that are held together by metallic bonds. Characterized by high melting points, can range from soft and malleable to very hard, and are good conductors of electricity.

Answer: A) 5040 Explanation: The Word LOGARITHMS  contains 10 letters. To find how many 4 letter words we can form from that = P410 =10x9x8x7 = 5040.

Answer: A) bare Explanation: Bleak means an area of land lacking vegetation and exposed to the elements like deserts.

Answer: A) 25 m Explanation: A:B = 200 : 169A:C = 200 : 182 CB = CA×AB    182200×200169   => 182:169   When C covers 182 m , B Covers 169 mWhen C covers 350 m , B Covers 169182×350=> 325 m       So C beats B by (350 - 325) = 25 m.

The answer is 'X'. 1. It is the 24th letter in the alphabetical order. 2. XX (20 in Roman) 3. XXX is used to refer dirty.

Answer: C) Engine Explanation: Food is processed by the stomach to provide energy for the functioning of the body.Similarly, fuel is processed by the engine to provide energy for the functioning of automobile.

A Coin has a Head and tail but no body. Since the two sides of coin are called as heads and tails.

Answer: A) 11.11% decrease Explanation: If earlier he is getting Rs. 1  per hr and working for 1 hr, income = Rs. 1Now he is getting Rs 1.3333 per hr and working for 0.66667 hrs Then income for 0.66667 hrs = Rs. 0.8889. If payment per hr is increased by 33.33 %  and working hours dereased by 33.33%, then 11.11 % decrease in income.